1. Field of the Invention
This invention relates to tire curing presses, and especially presses having a cross beam that is moved vertically to open and close the press. In particular, the invention relates to the stabilization of this cross beam during the tire curing process.
2. Description of the Prior Art
In automatic tire presses, such as those used in the manufacture of radial cord tires, a torroidal uncured tire carcass is loaded in a bottom mold section when the press is open and the top mold section then closes on top. A segmented or a two-piece tread mold assembly may be provided, and it is moved to a closed position to provide the tread forming portion of the mold. Then a forming bag or bladder is inflated within the carcass prior to the closing the press to assist in shaping the tire during the curing process.
In automatic tire presses generally referred to as slide-back presses, the top mold section is mounted on a cross beam which moves directly upward after the curing operation and then laterally away from the bottom mold section which is mounted in the base of the tire press. This positions the shaped tire at a location where it may be stripped from the top mold section and dropped on a conveyor, or the like.
During the tire molding operation, the movable cross beam is subjected to substantial pressures, and the beam has a tendency to bow or bend. Such bowing or bending can have a deleterious effect on the tire molding operation if allowed to occur. Even a slight amount of bending or bowing causes the middle of the cross beam to be spaced from the base of the press. This spacing can change the registry of the upper mold section with the lower mold section and can adversely affect the quality of the tires produced by the mold. Similar problems can occur in tilt-back tire presses.
To prevent this bending or bowing of the cross beam, the cross beams have been made larger and stronger. However, this adds to the cost of the tire press. In addition, the larger heavier cross beam is more difficult to move when the press is opened and is more difficult to position as it closes.